Sonic method and apparatus for driving casings through earthen formations



April 2, 1968 G. BODINE, JR 3,375,884

A. SONIC METHOD AND APPARATUS FOR DRIVING CASINGS THROUGH EARTHENFORMATIONS 3 Sheets-Sheet 1 Filed Aug. 16, 1965 INVENTOR. ALBERT. Gr.BODIN 15,312.

I icy w A ril 2, 1968 A. G. BODINE. JR 3,375,884

SONIC METHOD AND APPARATUS FOR DRIVING CASINCTS THROUGH EARTHENFORMATIONS INVENTOR. FI E- I ALBERT G. Booms, 3'52.

ATTORN EV A ril 2, 1968 A. c. BODINE, JR 3,375,384

SONIC METHOD AND APPARATUS FOR VING CASINGS THROUGH EAR'IHEN FORMA FiledAug. 16, 1965 3 Sheets-Sheet 5 INVENTOR. 7 ALBERT G. Booms, Jra.

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ATTORNEY United States Patent 3,375,884 SONIC METHOD AND APPARATUS FORDRIVING CASINGS THROUGH EARTHEN FORMATIONS Albert G. Bodine, Jr., 7877Woodley Ave., Van Nuys, Calif. 91406 Filed Aug. 16, 1965, Ser. No.479,868 9 Claims. (Cl. 175-22) ABSTRACT OF THE DISCLOSURE A first casingstring is driven into an earthen formation by means of sonic energywhich is applied to the casing to cause resonant standing wave vibrationthereof. When this string has been driven to a predetermined maximumdepth, a second smaller diameter casing string having a substantiallygreater length than the first string is placed in internal concentricitytherewith to form a new driving member which is driven by means ofsonicenergy applied thereto to cause resonant standing Wave vibrationthereof. Additional casings of succeedingly smaller diameter and greaterlengths are driven in like fashion until the desired depth is reached.The walls of casing members as they are driven are substantiallysonically uncoupled from the opposing walls of the externally concentricadjacent casing member such that the Q of the vibration circuit isincreased to make for higher sonic energyat the driving end of thecasing.

This invention relates to a sonic method and apparatus for drivingcasings through earthen formations, and more particularly to such amethod and apparatus particularly suitable for making very deep bores.

The utilization of acoustical energy in driving elongated members, suchas piles and casings into the earth, is described in my Patent No.2,975,846. In the technique described in this patent, a pile member issonically vibrated by means of an orbiting mass oscillator to producestanding wave vibration of such pile member. The resultant high levelsonic energy enables the pile to bore through the earthen formation in ahighly efiicient fash- 101].

In making very deep bores, i.e., of the order of several thousands offeet, as in the driving of oil wells, the Wall friction between thegreat lengths of casingutilized and the surrounding earthen materialposes a severe limitation on the efliciency of the system. Thus, suchfrictional eifects greatly lower therelfective 'Q of the acousticallyvibrating system, severely limiting the amount of acoustical energyavailable at the lower end of the casingwhere the driving is beingaccomplished.

To facilitate the comprehension of this problem and the techniquesutilized in the device of the invention to overcome same, it is helpfulto analogize the acoustically vibrating circuit involved to anequivalent electrical circuit. This type of analogy is Well known tothose skilled in the art and is described, for example, in chapter 12 ofSonics by Hueter and Bolt, published in 1955 by John Wiley and Sons. Insuch an analogy, force, F, is equated with electrical voltage, E;velocity of vibration, u, is equated with electrical current, i;mechanical compliance, C is equated with electrical capacitance, C mass,M, is equated with electrical inductance, L; mechanical resistance(friction), R isequated with electrical resistance, R; and mechanicalimpedance, 'Z is equated with electrical impedance, Z Thus, it can beshown thatif a member is elastically vibrated by means of an acousticalsinusoidal force, F, sin ml, to being equal to 271' times thefrequencyof vibration, that 1 F Sin wt 3,3 75,884 Patented Apr. 2, 1968Where wM is equal to l/wC a resonant condition exists, and the effectivemechanical impedance, Z,,,, is equal to the mechanical resistance, Rreactive impedance components wM and l/wC cancelling each other out.Under such a resonant condition, velocity of vibration, a, is at amaximum, effective power factor is unity, and energy is most efficientlydelivered to a load to which the resonant system may be coupled. It issuch a high efiiciency resonant condition that is preferably utilized inthe technique and devices of this invention to achieve the desired endresults.

Just as in electrical circuitry, maximum acoustical energy can betransferred from one circuit element to another where a good impedancematch exists, i.e., where the two elements have like impedances. Thisfact becomes particularly significant in the method and apparatus of theinstant invention where energy transfer from the penetrating end of thecasing to the earthen formation is necessary to cause the disintegrationof such formation in effecting the driving operation. By observation ofEquation 1 it can be seen that the impedance, Z is high where the force,F is high, and velocity of vibration, u, is relatively low. Thus, inview of the high impedance characteristics of earthen formations, it isdesirable that the penetrating end of the casing exhibit high impedancecharacteristics, i.e., that high force conditions exist at this point.

Also of particular significance in the instant invention is theattainment of high acoustical Q in the casing to markedly increase theetiiciency of the vibration thereof and to provide a maximum amount ofcyclic energy for the driving operation. As for the equivalentelectrical circuit, the Q of an acoustically vibrating circuit isdefined as the sharpness of resonance thereof and is indicative of theratio of the energy stored in each vibration cycle to the energy used ineach cycle. Q is mathematically equated to the ratio between wM and wRThus, the eifective Q of the acoustically vibrating circuit can bemaximized to make for highly etlicient high amplitude vibration byminimizing the effective friction in the vibrating circuit, and/ormaximizing the eflfective mass in such circuit.

In considering Equation 1 it should be kept in mind that this equationrepresents the total effective resistance, mass, and compliance in theacoustically vibrating circuit, and that these parameters are generallydistributed throughout the system rather than being lumped in any onecomponent or portion thereof.

The method and apparatus of this invention overcomes the shortcomings ofprior art sonic boring techniques by providing means forsmaintaining theextended casing, in a high Q condition even where it has been run aconsiderable distance into the ground. Longer columns in fact oftenexhibit even higher Q characteristics than shorter ones by virtue oftheir greater mass. This end result is achieved by freeing the sides ofall but the lowermost portions of the penetrating casing from contactwith the earthen formation, thus considerably lowering the friction ofthe vibrating system. The very end .of the casing remains in contactwith the earthen formation, thus forming a high frictional portion ofthe acoustical circuit having high impedance characteristics, wherebyenergy is effectively transferred at this point to the earthen formationto enhance the penetrating therethrough.

The desired end result is achieved in the device of the invention byutilizing a plurality of concentric casing strings of progressivelysmaller diameters, which are successively utilized as the drivingmembers. As each concentric casing reaches its predetermined maximumdepth, a new smaller diametered casing member is placed in internalconcentricity therewith to form a new driving member, and when this newdriving member has reached a predetermined penetration into the earthfornration, the first casing member is withdrawn. During actual drivingof the second casing the outer casing is left in place, in this mannerleaving the upper sides of the second member free from the surroundingearthen formation. In this manner, successive casing members havingsubstantial portions of their longitudinal extents free from frictionalcontact with the earth formation, and thus having high Qcharacteristics, are utilized.

Sonic energy is coupled to each successive penetrating casing memberfrom an orbiting mass oscillator, the vibrational output of which istightly coupled to the casing. Acoustical energy is applied to thecasing at a sonic frequency such as to set up a relatively large numberof standing waves in such casing. The orbiting mass oscillator and thecasing form a resonant system, such that the frequency of the output ofthe oscillator tends to lock in to maintain resonant vibration of thecasing with changes in the parameters of the system. With a relativelylong casing member having a high order of harmonic vibration at thevibration frequency, resonant frequencies for varying conditions areclosely spaced making it relatively easy for the system to adjust itselfto optimum resonant operation.

It is therefore an object of this invention to facilitate the sonicdriving of casings through earthen formations.

It is a further object of this invention to improve the efficiency inthe driving of casin g members through earthen formations.

It is still another object of this invention to minimize the frictionaleffects on a casing member in the making of deep bores through earthenformations.

It is still another object of this invention to substantially increasethe Q of a casing member in a sonic drive system.

It is still a further object of this invention to provide maximumtransfer of sonic energy from a sonic source to the penetrating end ofan earth penetrating casing.

Other objects of this invention will become apparent from the followingdescription taken in connection with the accompanying drawings of which,

FIGS. la-le are illustrations showing the technique of the invention,

FIG. 2 is an elevation view showing a preferred embodiment of the deviceof the invention in operation,

FIG. 3 is a view of the preferred embodiment of the device of theinvention as taken along the plane indicated by 3-3 in FIG. 2,

FIG. 4 is an elevation view of the preferred embodiment of the device ofthe invention as taken along the plane indicated by 44 in FIG. 3,

FIG. 5 is a schematic view illustrating a drive mechanism which may beutilized to drive the orbiting mass oscillators of the device of theinvention,

FIG. 6 is a plan view partly in cross section illustrating the clampingmechanism utilized in the preferred embodiment of the device of theinvention, and

FIG. 7 is a cross sectional view as taken along the plane 7-7 indicatedin FIG. 6.

Referring now to FIGS. la-le, the technique utilized in carrying out theinvention is illustrated. As shown in FIG. 1a, a first casing 14 isdriven into the ground 11 by means of sonic driving equipment as to bedescribed in connection with FIGS. 2-6. When driving through relativelysoft soil, to prevent earthen material from entering the inside of thecasing, the end of casing 14 is capped off by a capping device 13, withthe soil formerly occupying the space now occupied by the casing beingcompacted down and out into the adjacent layers of soil. Where thepenetrating is being accomplished through harder earthen formations, thecasing 14 is left open ended and the earth particles are then removedfrom the inner portion of the casing by hydraulic means well known tothose skilled in the art. If so desired, a suitable coring tool may beutilized for such earth particle removal.

After casing 14 has reached its maximum practicable depth, a secondcasing 16 having a smaller diameter is inserted substantially ininternal concentricity with casing 14. The sonic oscillator drivemechanism is removed from casing 14 and attached to casing 16, andcasing 16 is then sonically .driven so that it drives into the earthenformation 11 as illustrated in FIG. lb. When casing 16 has reached itsmaximum practicable depth, casing 14 may be removed, leaving a spacing19 having loose earth therein between the walls of casing 16 and thewall of earthen formation 11 as shown in FIG. 10. Such removal may beaccomplished by clamping the sonic oscillator drive mechanism (notshown) to casing 14 and sonically driving the casing to loosen it fromearthen formation 11 while it is being drawn upwardly by a liftmechanism (not shown).

A third casing 17, smaller in diameter than casing 16, is then insertedin internal concentricity with casing 16 and sonically driven by theoutput of the sonic oscillator in similar fashion to that of the othercasings. Casing 17 is thus driven to its maximum practicable depth, asillustrated in FIG. 1d. Casing 16 can then be removed in the samefashion as described in connection with casing 14, to leave space 20having loose earth therein between the walls of casing 17 and theearthen formation, as shown in FIG 1e. This procedure can be continuedwith succeeding smaller diameter casing sections until the desired depthis reached.

As can be seen, by virtue of this procedure, a large portion of thecasing wall is freed from the earthen formation with only the lowerportions of this wall being imbedded in the soil. The relative portionof the casing wall which is freed increases substantially as the depthof boring increases, as can be clearly seen by reference to FIG. Id. Inthis manner, the Q of the casing is made high by decreasing the wallfriction thereof, such that very high energy is available at thepenetrating portions where needed. Thus, whereas with prior arttechniques, a substantial portion of the driving energy is dissipated inthe upper earth with which the casing is in close contact, in the methodof this invention, by virtue of the freeing of the upper casingportions, such dissipation of energy is eliminated and the casing isutilized as a high Q resonator which efiiciently transmits the energy tothe penetrating end of the casing where it is utilized to maximumadvantage.

Several other advantages accrue from the freeing of the casing walls.Firstly, the weight of the casing and its appended drive members isthereby free to provide a downward bias to aid in the driving operation.At the same time, the lower portion of the casing is held closely in theearth, thus preventing buckling and the generation of unwanted lateralparasitic vibrations. The high bias available by virtue of the freecasing portions assures high acoustic force and impedance where thepenetrating is being accomplished to assure maximum transfer of energyto the high impedance earthen formation. This highly efficient transferof energy is especially significant where shaft driving at substantialdepth into highly consolidated earth formations and where penetrationbecomes very difficult.

In clearing an earth boring, in applications such as oil well drilling,the technique of this invention permits tight penetration throughproblem areas such as salt domes and the like by virtue of the fact thatthe lower ends of the casing, where the driving is being accomplished,are tightly coupled to the earthen formation. This tight coupling isfurther enhanced by the sonic extraction of the upper casing sectionwhich tends to compact the earth around the inner remaining casingsection. The utilization of a relatively long high Q casing section,which is resonantly vibrated at a high order harmonic frequency,facilitates the maintenance of an optimum resonant frequency for thecolumn by virtue of the relatively close spacing of resonant frequencieswith changes in system parameters. Thus, for example, a small change inthe effective length of the casing will give rise to a new optimumresonant vibration frequency relatively close to the first.

If so desired, friction reducing means can be placed between the casingstringer members 14, 16 and 17. This may take the form of lubricatingoil or may 'be in the form of low friction surfacing material such as aplastic film coated on the opposing surfaces of the casings.

Referring now to FIGS. 2-6, a preferred embodiment of the device of theinvention is illustrated. Casing member 16 is tightly gripped byhydraulically actuated clamping jaws 20. Referring particularly to FIG.6, a hydraulic drive fluid is fed to each of inner cylinders 30 throughfluid inlets 27. Outer cylinder members 26 are slidably mounted on innercylinders 30 which are fixedly attached to frame member 32. Whenhydraulic fluid is caused to pass into the cylinders 30 through inlets27 from a hydraulic control device (not shown), outer cylinders 26 areurged away from frame 32 bringing clamping jaws 20 into tight clampingengagement with the wall of casing 16. It is to be noted that it isessential to the proper operation of the device of the invention thatthere be tight coupling between frame 32 and casing 16. At the sametime, it is necessary that the clamping mechanism be readily releasableso that attachment can be made to a different casing member as thedriving operation proceeds. These desired features of operation areeffectively achieved by the hydraulic clamping mechanism shown.

Referring particularly to FIGS. 2 and 4, the acoustical drive signal isgenerated by means of orbiting mass oscil lator 35, which includes eighteccentric rotors 37a-37h which are rotatably mounted on frame 32. Rotors37a-37h are driven by means of gas turbines 40 and 41, the output drivesof which are coupled thereto by coupling shafts 72a72h respectively.Rotors 37a and 370 are driven in one direction, while rotors 37b and 37dare driven in opposite direction by the output of turbine 40, whilerotors 37e and 3712 and rotors 37 and 37g are similarly driven inopposite directions by the output of turbine 41. The oppositelypositioned rotors along each rotation axis, for example, rotors 37a, 37gand 37d, 372, etc., are driven in the same direction.

This rotational drive is achieved by means of a gear train for eachturbine, as illustrated in FIG. 5. Thus, with the output shaft 45 of theturbine coupled to drive gar 49, gears 50 and 51 rotate in one directionwhile gears 52 and 53 are made to rotate in the opposite direction. The

drive shafts 56 and 57 for the rotors on one side (for example, 370 and37d) are driven by gears 50 and 51, respectively, while the shafts 59and 60 for the rotors on the opposite side (for example, 37a and 37c)are-driven by gears 52 and 53 respectively. The eccentric rotors 37a-37hare phased so that they act together to produce high mechanicalvibration along the longitudinal axis of casing 16 while lateralvibrations are effectively cancelled out by virtue of the equal andopposite forces produced by the rotating members along the transverseaxes. The orbiting mass oscillator tends to automatically adjust itsoutput frequency so as to maintain resonant vibration of the casing withchanges in the effective impedance thereof, such lock-in operationmaking for optimum elficiency in the utilization of the sonic energy.

The synchronous rotation of rotors positioned opposite each other alongcommon rotation axes is assured by means of rotational couplers 70 whichjoin together rotors 37a and 37g, 37b and 37h, 37d and 37e, and 370 and377. Coupler members 70, which rotate with their associated rotors, havethe additional function of counteracting the bending moments produced onthe rotation shafts by the rotating eccentric masses. This is achievedby virtue of the fact that coupler members 70 are crescent shaped (seeFIG. 7) and thus are eccentrically weighted so as to generate bendingforces on the support shafts to counteract the bending moment producedthereon by the rotors. Oppositely positioned rotors 37a and 37g, 37b and37h, 37d and 37e, and 370 and 37 f, are driven together in synchronousfashion by drive shafts 72a-72h respectively by virtue of the couplingprovided therebetween by means of coupler members 70.

Support frame 74 is attached by means of a pulley mechanism 75 to anappropriate derrick device which can be utilized to raise and lower theframe as necessary in performing the boring operation.

The device and apparatus of this invention .thus provide highlyeffective means for transferring maximum sonic energy to the penetratingportion of a casing. This end result is achieved by freeing the sides ofa substantial portion of the casing from the surrounding ground and bytightly coupling sonic energy to the top of the casing so that suchenergy is eificiently transferred to the penetrating casing portion.

While the method and apparatus of this invention has been described andillustrated in detail, it is to be clearly understood that this isintended by way of illustration and example only and is not to be takenby way of limitation, the spirit and scope of this invention beinglimited only by the terms of the following claims.

I claim:

1. A method fordriving a casing member into an earthen formationcomprising the steps of sonically energizing a casing string to causeresonant elastic vibration thereof, said casing string having a largerdiameter and a substantially shorter length than said casing member tocause said casing string to penetrate into said formation to almost itsentire length, the inner portion of said casing string being keptsubstantially free of material,

placing said casing member within said casing string in internalconcentricity therewith,

sonically energizing said casing member to set up resonant standing wavevibration thereof so as to cause said member to penetrate into saidformation, the walls of said casing member opposite the walls of saidstring being kept substantially sonically uncoupled from said casingstring and said earthen formation, and

sonically energizing said casing-string to cause resonant standing wavevibration thereof while drawing it upwardly to withdraw said string fromthe formation while said casing member is left in place.

2. A method for driving a first casing string through an earthenformation comprising driving ,a second casing string having a shorterlength and greater diameter than said first casing string into saidformation by sonically energizing said second casing string at one endthereof to cause resonant elastic vibration thereof as the other endthereof penetrates said formation, the inner portion of said secondcasing string being maintained substantially p y,

When said second casing string has almost entirely penetrated into saidformation placing said first casing string within said second casingstring substantially in internal concentricity therewith,

driving said first casing string into said formation by sonicallyenergizing said first casing string to set up resonant standing wavevibration thereof to cause said first casing string to penetrate intosaid formation to substantially its entire length, the walls of saidfirst casing string opposite the walls of said second string memberbeing kept substantially uncoupled from said second string member andsaid earthen formation, and

sonically energizing said second casing string to cause resonantstanding wave vibration thereof while drawing it upwardly to withdrawsaid second string from the formation while said first casing string isleft in place.

3. The method as recited in claim 2 and further including the initialstep of capping the penetrating ends of said casing strings to preventthe entry of earthen material into the inside portions thereof.

4. The method as recited in claim 2 wherein said casing strings areresonantly vibrated by means of an orbiting mass oscillator.

5. The method as recited in claim 4 wherein said orbiting massoscillator is successively tightly coupled to the upper portion of eachcasing string wall with each casing string sonic energization step.

6. A device for penetrating through an earthen forma tion comprising afirst casing member driven into said formation,

a second casing member having a smaller diameter and a greater lengththan said first casing member inserted within said first casing member,and

means for driving said second casing member into said formationcomprising a frame member,

orbiting mass oscillator means mounted on said frame member for causinglongitudinal resonant standing wave vibration of said second casingmember, said orbiting mass oscillator means including a plurality ofpairs of oppositely positioned eccentric rotors symmetrically mounted onsaid frame member,

means for connecting the rotors of each of said rotor pairs together,

means for rotatably driving said rotors to generate the longitudinalvibration, and

clamp means for tightly holding said second casing member to said framemember to provide close coupling of the vibrational output of saidoscillator means to said second casing member, the walls of said secondcasing member being substantially sonically uncoupled from the opposingwalls of said first casing member,

whereby said second casing member comprises a relatively high Qvibrating system with the penetrating end thereof transferring highsonic energy to said earthen formation to efficiently cause thefiuidization thereof.

7. The device as recited in claim 6 and further including frictionreducing means located between the opposing walls of said first andsecond casing members.

8. In a device for driving through an earthen formation,

a first casing member driven into said formation,

a second casing member having a smaller diameter and a greater lengththan said first casing member inserted within said first casing membersubstantially in internal concentricity therewith, and

means for driving said second casing member into said formationcomprising a frame member, orbiting mass oscillator means mounted onsaid frame member for causing longitudinal resonant standing wavevibration of said second casing member, the walls of said second casingmember being substantially sonically uncoupled from the opposing wallsof said first casing member, said orbiting mass oscillator meansincluding a plurality of pairs of oppositely positioned eccentric rotorssymmetrically mounted on said frame member, half of said rotor pairsbeing on one side of said second casing member and being driven in onedirection, the other half of said rotor pairs being on a side of saidsecond casing member opposite said one side thereof and being driven ina direction opposite said one direction, means for connecting the rotorsof each of said rotor pairs together, means for rotatably driving saidrotors to generate the longitudinal vibration, and means for holdingsaid second casing member to said frame member to provide close couplingof the vibra tional output of said oscillator means to said secondcasing member, whereby said second casing member comprises a relativelyhigh Q vibrating system with the boring end thereof transferring highsonic energy to said earthen formation to efficiently cause thefluidization thereof. 9. The device as recited in claim 8 and furtherincluding separate shaft coupling means for joining the rotors of eachof said rotor pairs together to provide synchronous rotation thereof,each of said shaft coupling means comprising an eccentrically weightedmass for counteracting the bending moments produced by the associatedrotors on their rotation shaft.

References Cited UNITED STATES PATENTS 739,268 9/1903 Shuman 6153.641,700,949 2/1929 Osborne 61-53.64 3,187,513 6/1965 Guild 17519 X3,195,659 7/1965 Goodman 175-55 3,224,514 12/1965 Hornstein et a1.175-55 3,280,924 10/1966 Povlovich 17555 CHARLES E. OCONNELL, PrimaryExaminer.

R. E. FAVREAU, Assistant Examiner.

